He seems to be missing the fact that all of his human subjects are walking on a flat level surface whereas Patty, is not. She is traversing an area littered with debris which requires greater clearance to walk through. When I walk off trail I have to raise my shins and knees much higher for my feet to clear the forest undergrowth. This is more than 73 degrees. Patty is about 2 to 2 1/2 feet taller than I am so it stands to reason she would have greater clearance. She would need a lesser angle than I would.

This next video is a little long in making the point but it compares an actor attempting to mimic Patty's motion.

They use an actor to mimic Patty's walk for a comparison. Since Patty was spotted in a creek bed she would have been moving up an incline to reach the treeline. As humans we have to lean forward when traveling up an incline so why wouldn't Patty?

Yet again our actor in the second video is on a level surface. It looks uncomfortable and odd. I think you can see why but Patty is on a sand/gravel bar littered with storm debris. She would have to raise her shins higher to clear the debris. We cannot see what's on the other side of the bar so we can't say what we should be seeing. We can't see her feet when she puts her weight on them as she is walking along. To me it means the view is obstructed by the sand/gravel bar making me wonder how they know the area is clear in front of her.

On the other side of this coin a creature that walks in the forest all the time would probably have a higher shin rise than humans who make flat surfaces for walking. The leaning I can't explain beyond the difference of an incline versus a level surface.

In my opinion both comparisons are invalid. The only thing they both show is that the humans are on a flat level surface and Patty is not.